TM 10-3930-669-20 WARNING Remove  all  jewelry  such  as  rings,  dog tags,  bracelets,  etc.    If  jewelry  contacts battery terminal, a direct short may result in  instant  heating  of  tools,  damage  to equipment,    and    injury    or    death    to personnel. NOTE Using wiring schematic to follow logic flow. CONTINUITY TEST (1)   Set multimeter select switch to OHMS. (2)   Check continuity between master cylinder pressure switch connector, terminals 1 and 2. (a)   If there is no continuity, replace master cylinder pressure switch (Pare 7-17). (b)   If there is continuity, master cylinder pressure switch is OK. (3)   Connect connector P21 on master cylinder pressure switch connector. (4)   Close engine access panel (TM 10- 3930-669-10). VOLTAGE TEST (1)   Remove diode module DM1 (Para 7- 33). (2)   Set multimeter select switch to VOLTS DC. (3)   Connect positive (+) multimeter lead to diode module DM1, terminal T2 cavity. (4)   Connect negative (-) multimeter lead to a known good ground. (5)   Set MAIN POWER switch to ON position (TM 10-3930-669-10). (6)   Set engine switch to ignition position (TM 10-3930-669-10). (a)   If there are not 22 to 24 Vdc present, perform Steps (7) and (8) below and repair wire 10B (see schematic Appendix F). (b)   If there are 22 to 24 Vdc present replace diode module DM1. (7)   Set engine switch to off position. (8)   Set MAIN POWER switch to OFF position. (9)   Install diode module DM1. 2-259